Robin's sister Sally-Ann - who will be donating marrow for the procedure - underwent her first tests on Friday (July 6) in advance of the operation.

"My sister, Sally-Ann, went through a lot of tests today in preparation for being my bone marrow donor. She was such a trooper," Robin wrote in a Facebook message to fans last weekend.

The journalist went on to joke that she was less composed while at her sister's side for the medical examination.

"[It was] a long day and she had a smile on her face the entire time. I, on the other hand, couldn't stop crying," she admitted. "I'm so moved by her unrelentless willingness to do whatever it takes to help me."